CuxS thin films were fabricated by electrochemical deposition (ECD) on indium-tin oxide coated glass substrates. The pH of the solution was adjusted by lactic acid, and Cu2.6S thin films were successfully deposited. CuxZnyS thin films were also deposited by ECD. CuxZnyS thin films deposited under the optimum conditions exhibited high optical transmission in the visible range, and its bandgap was about 3.2 eV. It was confirmed by photoelectrochemical measurements that CuxZnyS showed p-type conduction and photosensitivity. Thus, a p-type wide bandgap semiconductor was successfully obtained by ECD for the first time. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.042203jes] All rights reserved.